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dr.marty

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I have a 2018 Scarab with twin Rotax 150's they run about 600 rpm's apart, the dealer has computer synced them twice and nothing has changed. The dealer said they can't find anything wrong. Has anyone had this issue?
 

Dean P

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Is it even all thru from idle to WOT? I assume the sync button is highlighted?

Mine is off about 400 at idle but then balances out when on plane.
 

dr.marty

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Sync light is on. Under 2k rpm and at full throttle around 7k rpm the engine show to be running at the same rpm's
 

JetTech72

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My guess would be the PPS, sensors located in the helm, need to be tweaked to make their output closer.
That's probably where your issue is coming from.
 

Dean P

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My guess would be the PPS, sensors located in the helm, need to be tweaked to make their output closer.
That's probably where your issue is coming from.
Would you be able to take a picture of this sensor?
 

dr.marty

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Thanks for responding, I'm not sure what PPS sensor is. What does PPS stand for?
 

Dean P

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Thanks for responding, I'm not sure what PPS sensor is. What does PPS stand for?
I believe @JetTech72 is referring to TPS (Throttle Position Sensor). PPS stands for Pedal Position Sensor.

However, I'm not sure how to adjust/tweak the sensor. If I think of it, when I go home tonight, I'll look and see what's there.
 

JetTech72

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@Dean P I was really referring to the PPS, since each engine operate on his own PPS a slight variation between both would create a difference in engine RPM along the loadline. AT WOT they would be both at 100%. There is not adjustment that can be done with the TPS as the system is fly by wire, thus the TPS is controlled via the ECU.
 

Dean P

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@Dean P I was really referring to the PPS, since each engine operate on his own PPS a slight variation between both would create a difference in engine RPM along the loadline. AT WOT they would be both at 100%. There is not adjustment that can be done with the TPS as the system is fly by wire, thus the TPS is controlled via the ECU.
Thanks for the update! Just curious what does PPS stand for?
 

JetTech72

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@Dean P you had it correct my friend. PPS is the Pedal Position Sensor (The throttle controller for boat or acceleration pedal in a car) . It's the potentiometer telling the ECU "I want to go". The TPS (Throttle position sensor) is the throttle body opening which is driven by the ECU in a "fly by wire" operation. No more direct mechanical link between the pedal & throttle body.

In this case I think the signal from each potentiometer (PPS) are slightly out of synch.
 

dr.marty

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Thank you all for your response to my Scarab boat issue. This forum is great. Now should I just replace both PPS or just one and would a dealer have to reprogram/relearn, or flash the ECU after replacement of the PPS? The dealer that works on my boat has not been very helpful.
 

JetTech72

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There is no reprogramming to be done. The thing is that both PPS need to have there output lining up. Either you replace 1 or both trying to find a good match. or you tweak the bracket or play with the PPS installation. It's easier to do it when BUDS diagnostic tool is connected as you can see the PPS output of both at the same time & tweak the bracket accordingly.
 

dr.marty

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Thanks JetTech72 for all your help I am going to replace both and will let everyone know the out come
 

Dean P

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Thanks JetTech72 for all your help I am going to replace both and will let everyone know the out come
Do you have part numbers? May help other with same issues.
 

dr.marty

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I don't have the part number if you can supply me with the PPS number would be great. I wish you were in Tennessee so I could just hire you to install them. Thanks again
 

JetTech72

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epc.brp.com

JPS : 460304 & 460305
BRP : 277001726 & 277001727
 
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